In shared virtualized hosting environments, security concerns dictate that the contents of memory be wiped before allocation to prevent leaking information to another user. For example, when memory is allocated to a virtual machine instance without first scrubbing the memory, data from previous memory allocations may remain available for inspection by another user. It is thus possible for a user to collect information left behind by the virtual machines of other users. Such information leakage can be problematic because virtual machine users typically expect their information to remain private.
A simple solution is to simply scrub memory after every memory deallocation, before every memory allocation, or both. However, as virtual machine instances increase in size, considerable resources can be expended on memory scrubbing.